Ok. I installed a Pioneer DEH-5800MP headunit yesterday. No problems with the install but when it came to the wiring harness, the car audio store owner told me to use the harness that wouls include the factory amp utilizing the line level outputs on the head unit. The stereo sounded ok, but I knew that the 200w advertised on the head unit were not being utilized. This morning I rewired the speakers using the speaker-outs coming from the headunit. Lo-and-behold, thats where the 200w were hiding.
Short of the story is - BYPASS THE LOUSY FACTORY AMP. You will be much happier.
Oh yeah,
I have the "premium" sound sstem in my 99 Stang.
Tim
99 Mustang (TIMSSTANG)